With that in mind, here’s the list of Pokemon species that DO NOT nest:

Pokemon obtainable from 10KM eggs:

Dratini

Pineco

Larvitar

Mantine

Gligar

Chansey

Mareep

Baby Pokemon:

Pichu

Togepi

Cleffa

Magby

Igglybuff

Elekid

Smoochum

Regional Pokemon:

Mr. Mime

Kangashkan

Farfetch’d

Heracross

Corsola

Tauros

Tyrogue family:

Hitmonlee

Hitmonchan

Hitmontop

Amorphic Pokemon:

Ditto

Porygon

Grimer

Koffing

Others:

Stantler

Phanpy

Togetic

Unown

Lickitung

Tangela

And what about biomes?

As for biomes, almost all of these Pokemon have an assigned biome, however, it doesn’t have anything to do with Nests. For example, it’s known that Mantine is specific to Sea, Rivar and Lake biome and it’s rumored that Larvitar is specific to Mountain and Forest biome.

Remember that the understanding of Pokemon GO biomes is still very naive, so take these definitions with a grain of salt.